Asian carp have infested the Mississippi River and many of its tributaries. An electric barrier near Chicago is meant to keep them out of Lake Michigan, where scientists say they could spread to the other Great Lakes and disrupt existing fish populations.

The Coast Guard said Thursday its researchers have conducted experiments with a modified barge to determine whether Asian carp eggs or larvae could slip into ballast tanks and evade the barrier.

Test results suggest that even if tiny Asian carp got into the tanks, they'd have almost no chance of surviving the pumping system through which they'd have to pass to return to open water.